Snap-in contact for multiple connectors



A. F. DAMICO 3,075,169

SNAP-IN CONTACT FOR MULTIPLE CONNECTORS I Jan. 22, 1963 2 Sheets-Sheet 1 Filed June 13, 1960 Z2 Z4 Z3 2/ Anthony Amico ATTORNEY Jan. 22, 1963 Filed June 13, 196 0 A. F. UAMICO SNAP-IN CONTACT FOR MULTIPLE commcwoas 2 Sh eets-Sheet 2 281/8 15/ 266 5 I3 IINVGENTOR Anthony FDAm/co BY W ATTORNEY "s a c 2, a tinned i s 3,075,169 SNAP-EN CQNTA'CT FOR MULTIPLE tIfiNNECTURS Anthony F. EArnico, 1 9. Box 13251, llfiallas, 'liex. Filed Stone 13, rate, Ser. No. 35,633 3 Qiaims. (Q1. 339-217) This invention is concerned with a snap-in contact for multiple contact connectors. It is particularly concerned with a snap-in contact of the type employed for removably securing same in the bore of a passage provided through an electrical contact block or body on a connector plug in such a way that the contact is securely mounted in such passage, and cannot be withdrawn or disengaged from the passage except by a tool inserted into the passage to retract the spring-like retaining element.

Plug and receptacle connectors of the type in which this improvement is used are employed in electronics circuits, such as in computers and aircraft, where a great number of conductors are employed. Such plugs customarily consist of a block or body made of insulating material having a large number of wires or conductors attached thereto. The conductors are attached to contact elements removably disposed in passages provided through the block, and either a female spring-like receptacle or a male plug member, is provided adjacent the molding face of the block in such passage, so that the corresponding male or female member, as the case may be, of a companion plug may be inserted therein and held by frictional contact.

It has been the practice in the past to attach contacts fixedly in the passages and the conductors were soldered to the contacts on the terminal end of the block. This practice has proven unsatisfactory because where there are a large number of contacts, it is difficult and tedious to solder the conductors to the contacts by reason of their close relationship, and often residue of solder caused shorting between the contacts, or the heat of the soldering operation burned and crystallized the material of the blocks.

Such manner of connection of the contact to the block also prevented the contacts from being removed from the block, without destroying the block, and the contacts disposed therein. It is desirable that such contacts be removably disposed in the passages through the block, because the contacts are often assembled in the wrong relationship and it is necessary to remove same to exchange passages in which they are placed, and it is desirable to be enabled to replace damaged connector elements.

Furthermore, it is desirable to eliminate the tedious, time-consuming and dangerous practice of soldering the connections to the contacts after they are placed in the passa es in the block.

Attempts have been made to provide contacts which were attached to the ends of the conductors prior to placing them in the passages and providing spring-like latches on the contacts to engage with shoulders or recesses in the passages so that they could be removed from the passages and inserted therein upon assembly. Such a device is illustrated in the Adams Patent No. 2,477,849, issued August 2, 1949.

However, such devices have proved unsatisfactory because they did not provide a firm and positive connection between the passage and the contact so that when unusual force was exerted against the conductors attached to the contacts, the contacts would often become disengaged from the passages. Furthermore, upon repeated removal of the contacts from the passages, the retainer elements would become distorted or worn to such an extent that they would not retain the contacts in the passages. The contacts shown in the Adams patent are held in place ice in the passages through the plug block by means of a split sleeve spring element, having an angularly, outwardly extending flared end thereon arranged to come into contact with a complementary shoulder in the passage and a conical head on the contact which comes into contact with the outwardly flared end of the retainer, so that when force is exerted against the conductor attached to the contact, an outwardly acting force component is exerted between the conical head and the outwardly flared end of the retainer. Such laterally acting force component may be great enough to expand the passage to such an extent as to allow the retainer member to escape between the shoulder in the passage and the conical head, to thereby allow the contact to become disengaged from the block, or the force may be great enough to actually break or crack and rupture the connector block, thereby allowing the connector element to escape from the passage, or damage the block to such an extent that it would have to be replaced.

Furthermore, the female spring-like end of the connectors in devices such as that shown in the Adams patent were split or slotted, and the split portion was bent inwardly to provide a tension for assuring electrical contact between the male prong of a complementary connector and the female receptacle. This not only required a plurality of operations to make such a female connector, but it did not provide a satisfactory and firm electrical contact. I

This invention is intended to overcome the above related defects and others in devices of the type indicated.

I have provided a removable electrical contact of the type described, including a retainer member, which in cooperation with the connector element and the bore through the block firmly secures the contact within the bore of the block so as to prevent escape therefrom, until released by a tool inserted within the bore.

The retainer element comprises a split spring-like sleeve element providing prongs having an outwardly extending flange on the ends thereof with a recess therein arranged to receive a shoulder disposed on the contact member, which looks the prongs against a corresponding shoulder in the bore of the block in such a way that the prongs cannot move inwardly to escape from engagement between the shoulder on the contact member and the corresponding shoulder in the bore of the block, and the relationship between the shoulders on the contact member, the retainer member and in the bore is such that when a force is exerted longitudinally of the contact member on the electrical conductor attached to the contact, such force acts longitudinally and parallel to the axis of the bore, and does not act laterally of the bore, as in previous devices, such as that disclosed in the Adams patent. There is no outwardly laterally acting force against the block, which could expand the bore, or crack or destroy the material of the block.

Moreover, due to the fact that the outwardly extending flange on the retainer member is firmly locked between the shoulder on the contact member and the shoulder in the bore between substantially straight surfaces, there is no tendency for the spring-like prongs to be forced inwardly and the flange on the retainer member cannot escape from between the shoulders, when force is exerted against the conductor attached to the contact in a direction having a tendency to pull the contact out of the bore of the block. In other words, the greater the pull or force exerted on the contact, the firmer the shoulder or flanges on the prongs of the retainer member will be clamped between the shoulders on the contact and in the bore.

111 applicants construction there has also been provided a female receptacle on the connector member, having a aerated split slot therein as in previous devices, but having an inwardly turned bead thereon which is formed previous to splitting the receptacle so as to provide a firm electrical contact between the male member when inserted therein.

Such construction also provides economy in manufacture in that the head can be formed about the receptacle prior to cutting the slot, and it is not necessary to provide an additional operation after cutting the slot or bending or deforming the free portion of the receptacle inwardly to provide a spring-like connection between the male member and the female receptacle.

It is, therefore, a primary object of the present invention to provide a snap-in contact connection between the contact plug bore, including retainer means, which on cooperation with the contact and the shoulder provided in the bore, provides a firm, positive and secure attachment of the contact in' the passage of the block, in such a manner that unusual longitudinal forces exerted onthe conductor attached to the contact, will not have a tendency to distort or break the material of the plug, and which provides a connection wherein the retainer member prongs do not have a tendency to move inwardly to escape between the cooperating shoulders on the connector and in the bore of the plug.

It is another object of the invention to provide such a contact member having female receptacles provided with a slotted portion and having an inwardly turned bead thereon to provide a firm connection between a male member inserted in such receptacle and the female receptacle of the contact.

A specific object of the invention is to provide such a connector member and a retainer member therefor for securing same in the bore of a block wherein force exerted against the contact member acts longitudinally thereof and does nothave outwardly or laterally acting force component which could cau'sedamag'e or destruction of the material of the block.

Other and further objectsof the invention will'become apparent upon reading the detailed specification hereinafter following and by reference to the drawings annexed hereto.

A suitable embodiment of the invention is shown in the attached drawings wherein:

FIGURE I shows typical male and female electrical contact plugs or blocks, incorporating my improvement, as they would be shown in joined condition;

FIGURE II is an end view of the retainer member;

FIGURE III is a side elevational view of the retainer member;

FIGURE IV is a partially sectionalized view of the retainer member taken on the line lV-IV of FIG. II;

FIGURE V is a perspective view of the retainer menr ber;

FiGURE VI is a side elevational, partially sectionalized view of the contact member and retainer assembly as it would appear While being-inserted in the bore of a connector block;

FIGURE Vll is a view similar to FIG. VI showing the contact member and retainer member assembly in position in the bore of the connector block before outward force is exerted on the conductor;

FIGURE VIII is a view similar to FIG. VI, showing the position of the contact and retainer with the shoulders thereon, and on the retainer and in the bore in contact;

FIGURE IX is an enlarged fragmentary view showing the. relationshipv between the shoulders on the retainer member, the contact, and the bore of the block when in locked position in the bore; 7

FIGURE X is a transverse sectionalized view showing the retainer member disposed about the contact and disposed in the bore of connector block; and

FIGURE Xi is a side elevational view, partially sectionalized, of the removal tool for disengaging the retainer member from engagement with the shoulder in the bore of the contact block.

The female contact block is indicated by the numeral 1 and has a molding face 1:: thereon, and a contact face lb thereon.

The male contact block 2 has a molding face 2a thereon, and also includes a contact end 2b.

A plurality of conductors 3 are attached to the contact elements disposed in the bores extending through the male plug 2, and there are a plurality of conductors 4 attached to the female contact members disposed in the bores of the female contact block 1.

The improvement constituting the present invention will be described in connection with a female contact member, but it will be understood that the improvement would also be applicable to a male contact member.

As shown in the drawings, the female block member 1 has a plurality of longitudinal bores 5 extending therethrough. Each bore 5 has a reduced diameter portion 6, with the counterbores 7 and 8 at each end thereof.

An electrical contact member 9 is disposed in the bore.

The contact member 9 has a hollow wire-engaging end to into which the end of one of the conductors 3 is inserted, and may be secured therein by solder admitted to the interior of the hollow end 10 through the hole 10a, or the conductor could be crimped to the hollow end it? after the end of the conductor is inscrtedtherein. Any manner of secure connection of the conductor to the hollow end 10* of the contact 9 would be satisfactory.

A hollow female receptacle is disposed on the other end of the conductor of the contact element 9, the hollow ends 10 and 11 being connected by a solid reduced diameter mid-portion 13.

The hollow female receptacle 7 is slitted, as indicated at 14, to provide a spring segment 15 thereon. Prior to forming the slit 14 in the receptacle 11, an inwardly turned bead 16 is formed thereabout by a suitable die which may be inserted in the end thereof and rolled against the corresponding element of such die. The head 16 provides an inwardly extending annular portion with which the male prong 12 comes into contact as it is inserted within the receptacle 11, and as the male prong 12 is forced past the inwardly turned bead 16, the spring segment 15 is forced or sprung outwardly to allow the male prong to pass over the inwardly extending bead 16 Thereby there is provided a firm electrical contact between the male element 12 and the female receptacle 11.

The retainer device, or looking sleeve, is shown best in FIGS. II-V. Such retainer element includes a sleevelike body 18 which is provided with a split portion 19, constituting a segmental space less than half the diameter .of such sleeve. The split 19 is also less in width than the diameter of the reduced mid-portion 13 of the contact 9. The retainer member 18 is made up of springlilte material so that it may be deformed outwardly to force the split portion 19 over the reduced mid-portion 13 and will spring back into its original form about the reduced mid-portion 13, whereby it is retained thereon in the manner shown in FIG. X..

' A plurality of slits 29 are formed in the sleeve member 18, which extend only part way of the length thereof to provide a plurality of spring prongs 21 thereon.

The spring prongs 21 have flared, outwardly extendingends 22 thereon, having arcuate recesses 23 formed therein.

The arcuate recesses 23 are in aligned and coinciding annular relationship, and include a straight, continuous shoulder 24 therein. The straight shoulder 24 is arranged to extend at substantially right angle to the axis of the bore 5 extending through the connector block for. the purpose which will be hereinafter related.

A. tapered guide surface 25 is provided as a part of the recess 23 and. merges into, and joins with, the straight surface 24, such guide surface 25 being for the purpose of guiding the enlarged female receptacle it into such recess in the manner which will be hereinafter explained.

A strai ht right angular shoulder 26 is provided on the terminal end 16 of the contact 9, and the end of the retainer element 18 is arranged to come into contact therewith and thereby limit the movement of the retainer element 19 on the contact element, when the retainer element is disposed about the reduced diametrical portion 13 of the contact element.

A shoulder 27 is provided in the bore 5 of the contact block, with which the shoulder 26 on the contact element 9 may engage in order to limit the inward movement of the contact element in the bore.

Another shoulder 28 is provided in the bore 5 which is engageable with the flared ends 22 on the prongs 21 to limit the movement of the retainer element 1% and the contact element 9 engaged therewith inwardly of the bore, when a force is exerted against the conductor 3 attached to the contact element 9.

An outer annular substantially right angular shoulder 29 is provided on the inner end of the female receptacle 11, which is arranged to come into contact with the straight shoulder 24 in the recess 23 of the retainer member 18.

As is best shown in FIG. VII, a space 3t) is provided between the end of the retainer sleeve 18 and the shoulder 29, when the contact element is pushed inwardly, so as to permit the retainer element to be sprung inwardly by a tool inserted in the counterbore S, for removal of the contact element and retainer element from the bore, in the manner hereinafter described.

As shown in the enlarged view of FIG. IX, the flared end 22 of retainer 18 is spaced from the wall of the counterbore 8 as indicated at 3 5, to permit the tubular removal tool 32 to be inserted thereover to thereby spring the prongs 21 inwardly to allow the retainer element and contact element to be removed from the bore of the contact block, as will be described.

The removal tool 32 includes a bore 33 arranged to be slipped over the female contact element 15 and has a cylindrical wall portion 34 terminated at the outer end by an outwardly extending beveled surface 35' to provide a guide surface for slipping the end of the removal tool 32 over the flared end 22 to spring same inwardly to permit the removal of the retainer member and the contact element from the bore of the contact block.

The operation and function of the device is described as follows:

The retainer element 18 is placed about the reduced mid-portion 1'3 of the contact member 9 in the manner hereinbefore described. The contact member and retainer element are then inserted through the counterbore 7. When the outwardly flared ends 22 of the spring prongs 2-1 of the retainer element 13 contact the tapered shoulder 27 in said bore, the prongs are cause to spring inwardly to permit them to enter and slide along the reduced diameter 6 of the bore 5.

When the outwardly flared ends 22 of the prongs 21 reach the counterbore 8, the prongs Z1 spring outwardly to normal position and the shoulder 22;! ther on is in position to contact the shoulder 28, as shown in F1". VII.

When force is exerted on the conductors 3 attached to the contact element 9 in the direction indicated by arrow at 31 in FIG. 1X, the straight shoulder 29 comes into contact with the straight shoulder 24- in the recess 23 provided in the ends of the prongs Z1, and firmly locks the flared end 22 between the shoulders 23 and 29.

It will be noted that by reason of the contact between the straight shoulders 24 and 29 and the straight shoulder 28, against which the flared ends 22 of the prongs 21 are engaged, the force on the contact element 9 when a pull or force is exerted on the conductors 3, is completely a longitudinal force, parallel to the axis of the bore 5 as indicated by the arrow 31. There is no lateral or outwardly directed force as in previous devices such as shown in the Adams patent. Therefore, there is no tendency to expand or rupture the material of the connector block 1 by laterally directed force as in previous devices. Since the component of force is longitudinal of the axis of the bore 5, it would be necessary to shear the reduced diameter portion 6 from the bore in order to permit the connector member to escape from the bore. Before such force would be exerted, the conductor 3 would probably be broken or pulled from engagernent with the end it) of the connector.

It will also be noted that when a force is exerted on the connector member in the direction indicated at $3, andthe shoulders Z) and 2d, and shoulders 28 and 22a are in engagement, the flared end 22 of prongs 23; cannot move inwardly, to permit the retainer member to become disengaged from between the shoulders 29 and 28. Furthermore there is no tendency of the ends of the prongs to creep up and distort between the connector element and the bore Wall was the case in the device of the Adams patent wherein the ends were tapered outwardly in a conical shape, and were engaged with a conical surface on the connector member.

To disconnect the contact from the bore of the connector block 1, the connector member is pushed inwardly to provide a space 30 between the shoulder 29 and the flared ends 22 of the prongs 23. The removal tool 32 is then inserted in the counterbore 8 over the female receptacle ill so that the wall portion 34 is forced into the annular space 36 to thereby move the spring prongs 21 inwardly to such an extent to allow them to come under the shoulder 12% and reduce the diameter thereof to such an extent as to allow them to enter the reduced bore 6. While such removal tool 32 is thus in place, the connector member 9 is pulled outwardly to slide the prongs 21 along the reduced diameter bore '6 and thereby permit the removal of the connector member from the bore.

it will therefore be seen that l have Provided a means for removably attaching a contact or connector member within the bore of a connector plug in such a manner that it is securely mounted therein, and in which any force eX- erted thereagainst upon the conductor member attached thereto, will be in a direction parallel to the axis of the bore and the connector member so that no outwardly acting lateral component of force is exerted against the material of the connector plug whereby the material of the connector plug might be expanded or ruptured; and I have also provided a retainer element which, in cooperation with shoulders in the bore of the connector plug and the contact, positively prevents the inward movement of the retainer member to allow same to become disengaged, by force exerted outwardly on the conductor attached ther to. I have also provided improvement in the female receptacle in such a connector member, which provides a iirrn electrical contact with the male member of the companion connector.

it will be understood that only one preferred embodimen-t of the invention is shown in the drawings, and that other forms and modifications can be made without departing from the spirit and scope of the appended claims.

Having described by invention, I claim:

1. in a device of the class described, a. connector plug body having a bore therethrough; a removable connector member inserted in the bore including, a conductor connection end; an electrical contact end; a reduced mid-portion connecting said ends; a retainer element constituting a split sleeve extending over the reduced mid-portion of the connector; a plurality of slits in said sleeve providing spring prongs thereon; an outwardly extending arcuate flange on the outer end of each of said spring prongs; a recess in the end of each flange; a shoulder having a surface lying in a plane normal to the axis of the bore in each of said recesses; an annular shoulder on the contact end arranged to come into contact with the shoulders in the recesses; and a shoulder in the bore having a surface lying in a plane normal to the axis of the bore arranged to contact the sides of the flanges opposite the contact end shoulder. I

2. In a device of the class described, a connector block; a bore through said block including a reduced diameter portion and counter bores in each end thereof, the counter bores forming spaced shoulders in the bore at least one of which has a surface perpendicular to the bore axis; a contact member having a conductor connection end and a plug-in connection end thereon, said ends being connected by a reduced diameter portion providing spaced shoulders thereon; a retainer member comprising a split sleeve arranged to be disposed about the reduced diameter portion of the contact member; said retainer sleeve having a plurality of slits therein, forming spring prongs thereon; a recess formed in the end of each of said prongs, providing a straight substantially right angular shoulder therein having a surface perpendicular to the axis of the bore; an external shoulder about the end of each of the prongs opposite the shoulder in the recess, arranged to come into contact with the perpendicular shoulder in the bore; the shoulder on the plug-in connection end being arranged to come into contact with the shoulders in the recesses, and the shoulder on the conductor connection end being arranged to come into contact with the other shoulder in the bore; the outwardly extending ends of the prongs bein clamped between the shoulder on the plug-in connection end and the perpendicular shoulder in the bore when force is exerted outwardly on the conductor connection end of the contact member, whereby a force acting parallel to the longitudinal axis of the bore is exerted against the retainer member, and substantially no lateral force is exerted against the Wall of the bore.

3. The combination called for in claim 2 wherein the shoulders on the contact member are spaced apart a sufficiently greater distance than the spacing between the shoulders in the bore to allow longitudinal movement of the shoulder on the plug-in connection end out of the recesses to permit the prong-s to be sprung inwardly for removal through the reduced diameter portion of the bore,

References Cited in the file of this patent UNITED STATES PATENTS 2,477,849 Adams Aug. 2, 1949 2,557,746 lngham June 19, 1951 2,781,498 Maly Feb. 12, 1957 FOREIGN PATENTS 1,188,936 France Mar. 16, 1959 

1. IN A DEVICE OF THE CLASS DESCRIBED, A CONNECTOR PLUG BODY HAVING A BORE THERETHROUGH; A REMOVABLE CONNECTOR MEMBER INSERTED IN THE BORE INCLUDING, A CONDUCTOR CONNECTION END; AN ELECTRICAL CONTACT END; A REDUCED MID-PORTION CONNECTING SAID ENDS; A RETAINER ELEMENT CONSTITUTING A SPLIT SLEEVE EXTENDING OVER THE REDUCED MID-PORTION OF THE CONNECTOR; A PLURALITY OF SLITS IN SAID SLEEVE PROVIDING SPRING PRONGS THEREON; AN OUTWARDLY EXTENDING ARCUATE FLANGE ON THE OUTER END OF EACH OF SAID SPRING PRONGS; A RECESS IN THE END OF EACH FLANGE; A SHOULDER HAVING A SURFACE LYING IN A PLANE NORMAL TO THE AXIS OF THE BORE IN EACH OF SAID RECESSES; AN ANNULAR SHOULDER ON THE CONTACT END ARRANGED TO COME INTO CONTACT WITH THE SHOULDERS IN THE RECESSES; AND A SHOULDER IN THE BORE HAVING A SURFACE LYING IN A PLANE NORMAL TO THE AXIS OF THE BORE ARRANGED TO CONTACT THE SIDES OF THE FLANGES OPPOSITE THE CONTACT END SHOULDER. 